Different displays may differ significantly in supported colors (or gamut), achievable dynamic ranges, white points, spatial resolutions, etc. A standard dynamic range (SDR) display has a narrow dynamic range, and thus a very limited ability to render images that have lightness variations exceeding the narrow dynamic range supported by the SDR display. A high dynamic range (HDR) display has a dynamic range much higher than that of an SDR display, and thus a much larger ability to render images that have relatively large lightness variations.
While an image is normally intended to be rendered exactly according to the creative intent, in cases where capabilities of a display are constrained, a display management (DM) algorithm could be used to algorithmically map the image to device-dependent values within the display's capabilities. Under display management, highlights in images could be mapped up to different maximum brightness levels that are respectively supported by different displays. However, highlights as rendered under existing approaches could cause the same image to look disparately different to viewers from display to display.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section. Similarly, issues identified with respect to one or more approaches should not assume to have been recognized in any prior art on the basis of this section, unless otherwise indicated.